Megamax C is a K&R implementation of C for the Atari ST, Apple IIgs, and Macintosh computers. Sold by Megamax, Inc., based in Richardson, Texas, the package includes a one-pass compiler, linker, editor, resource construction kit, and documentation. In the early days of the Atari ST, Megamax C was the primary competitor to the Alcyon C compiler from Digital Research which was included in the official developer kit from Atari. According to a review in Antic magazine, Megamax C compiled a small benchmark program six times faster than Digital Research's compiler.
Megamax C was written by Michael Bunnell with Eric Parker providing the linker and most of the standard library. A later version of the compiler was renamed Laser C, while the company remained Megamax.